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A sequence of 88 m of continuous borehole cores of Lower Cretaceous shallow water
carbonates from Southern Italy was obtained and studied lithologically and
palaeomagnetically. It was found that the rocks are organized in cyclic lithofacies
representing depositional environments from subtidal to supratidal and their magnetic
remanences are all measurable and stable even if very weak. Cyclicities in the Milankovitch
band were found using F.F.T analyses in both the sedimentological and palaeomagnetic
records, and these matched the astronomical periodicities predicted for the Early
Cretaceous. From this link it is possible to date the absolute time represented by the
sediments, and the absolute time of acquisition of the palaeomagnetic signal. The
palaeomagnetic signal is independent of sedimentological characteristics and lithofacies
organization. The mean palaeolatitude and the tectonic results are consistent with other
Lower Cretaceous structures in the Southern Apennines. The palaeomagnetic data,
although still being studied, also shows shorter wavelengths signals than the Milankovitch
cycles, some of which are likely to be comparable with secular variations of the
geomagnetic field in the Early Cretaceous. Polarity changes are present, which correlate to
the Geomagnetic Polarity Scale. Longer Normal polarities were found at about 1,000,000
years and in them the secular variations were found longer than usual. A repeatable
magnetic behaviour characterises the polarity changes each about 230,000 years. It is
hypothesized that climatic variations and the sea level oscillations affect the thickness, type
and cyclicities of sediments and geomagnetic variations control the palaeomagnetic data.
This study confirms that ultra-high resolution magnetostratigraphy can be undertaken on
shallow water carbonates.

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All items in PEARL are protected by copyright law.
Author manuscripts deposited to comply with open access mandates are made available in accordance with
publisher policies. Please cite only the published version using the details provided on the item record or document.
In the absence of an open licence (e.g. Creative Commons), permissions for further reuse of content should be
sought from the publisher or author.